Ecological evaluation of gadolinium toxicity compared with other heavy metals using an aquatic microcosm.

ガドリニウムは産業や医療分野でその利用量が増大しつつあるにもかかわらず、生態系に対するガドリニウムの毒性評価が十分に行われるとは言えない。そこで水系マイクロコズムを用いガドリニウム毒性の評価を行った。マイクロコズム構成微生物に対するガドリニウムの毒性は銅やニッケルと同等であり、マンガンの約100倍であった

Extended-Spectrum-β-Lactamase-Producing Escherichia coli Strains Isolated from Farm Animals from 1999 to 2002: Report from the Japanese Veterinary Antimicrobial Resistance Monitoring Program

A nationwide surveillance for antimicrobial susceptibility in Escherichia coli strains isolated from food-producing animals in Japan was conducted from 1999 to 2002. Eighteen cefazolin-resistant E. coli strains were isolated from broilers. Six were CTX-M-type producing, and eight were CMY-2 producing, while eight had mutations at the ampC promoter region

Germ-Free Conditions Modulate Host Purine Metabolism, Exacerbating Adenine-Induced Kidney Damage

Alterations in microbiota are known to affect kidney disease conditions. We have previously shown that germ-free conditions exacerbated adenine-induced kidney damage in mice; however, the mechanism by which this occurs has not been elucidated. To explore this mechanism, we examined the influence of germ-free conditions on purine metabolism and renal immune responses involved in the kidney damage. Germ-free mice showed higher expression levels of purine-metabolizing enzymes such as xanthine dehydrogenase, which converts adenine to a nephrotoxic byproduct 2,8-dihydroxyadenine (2,8-DHA). The germ-free mice also showed increased urinary excretion of allantoin, indicating enhanced purine metabolism. Metabolome analysis demonstrated marked differences in the purine metabolite levels in the feces of germ-free mice and mice with microbiota. Furthermore, unlike the germ-free condition, antibiotic treatment did not increase the expression of purine-metabolizing enzymes or exacerbate adenine-induced kidney damage. Considering renal immune responses, the germ-free mice displayed an absence of renal IL-17A expression. However, the adenine-induced kidney damage in wild-type mice was comparable to that in IL-17A-deficient mice, suggesting that IL-17A does not play a major role in the disease condition. Our results suggest that the enhanced host purine metabolism in the germ-free mice potentially promotes the conversion of the administered adenine into 2,8-DHA, resulting in exacerbated kidney damage. This further suggests a role of the microbiota in regulating host purine metabolism

Nucleic acid sensing by T cells initiates Th2 cell differentiation

While T-cell responses are directly modulated by Toll-like receptor (TLR) ligands, the mechanism and physiological function of nucleic acids (NAs)-mediated T cell costimulation remains unclear. Here we show that unlike in innate cells, T-cell costimulation is induced even by non-CpG DNA and by self-DNA, which is released from dead cells and complexes with antimicrobial peptides or histones. Such NA complexes are internalized by T cells and induce costimulatory responses independently of known NA sensors, including TLRs, RIG-I-like receptors (RLRs), inflammasomes and STING-dependent cytosolic DNA sensors. Such NA-mediated costimulation crucially induces Th2 differentiation by suppressing T-bet expression, followed by the induction of GATA-3 and Th2 cytokines. These findings unveil the function of NA sensing by T cells to trigger and amplify allergic inflammation

A thermoprotective probiotic function by thermostable lactic acid bacteria and its causal structure

Global warming has become an urgent issue, and heat-stress protective materials should be developed to manage human life and animal husbandry. Here, thermoprotective effects of Weizmannia coagulans SANK70258, a thermostable probiotic lactic acid bacterium, are investigated using a broiler model in an artificial thermal climate facility. Probiotic exposure significantly enhances their growth even under heat-stress. Based on the characteristic omics data selected using machine learning (random forest and XGBoost), structural equations and causal inference for broiler growth under heat-stress estimate the strong relationship with pyridoxal involved in the reduction of hepatic oxalic acid, which is responsible for cold sensitivity. It is also estimated that faecal Pseudomonas, which can reduce pyridoxal, is reduced by probiotic exposure, and has a negative causal effect on growth. Thus, these observations suggest a novel probiotic aspect of W. coagulans that modulates the mechanism of heat tolerance related to the cold sensitivity

Estimation of symbiotic bacterial structure in a sustainable seagrass ecosystem on recycled management

Seagrass meadows play an essential role in blue carbon and aquatic ecosystem services. However, methods for the flourishing of seagrass are still being explored. Here, data from 49 public coastal surveys on the distribution of seagrass and seaweed around the onshore aquaculture facilities are revalidated, and an exceptional area where the seagrass Zostera marina thrives was found. The bacterial population there showed an apparent decrease in the pathogen candidates belonging to the order Flavobacteriales. Moreover, structure equation modeling and a linear non-Gaussian acyclic model based on the machine learning data estimated an optimal symbiotic bacterial group candidate for seagrass growth as follows: the Lachnospiraceae and Ruminococcaceae families as gut-inhabitant bacteria, Rhodobacteraceae as photosynthetic bacteria, and Desulfobulbaceae as cable bacteria modulating oxygen or nitrate reduction and oxidation of sulfide. These observations confer a novel perspective on the seagrass symbiotic bacterial structures critical for blue carbon and low-pathogenic marine ecosystems in aquaculture.Comment: 54 pages, 3 figures, 16 supporting informatio

Activation markers of human basophils: CD69 expression is strongly and preferentially induced by IL-3

Background: The biological functions of basophils are precisely regulated by various cytokines in vitro, but little is known about surface markers that are upregulated during the cytokine-mediated activation process. Objective: It has been well established that CD69, CD44, and CD54 represent "activation markers" for cytokine-mediated eosinophil activation. The objective of this study was to elucidate the expression and regulation of these molecules in human basophils in vitro as well as in vivo. Methods: Basophils were purified from venous blood by means of density gradient centrifugation followed by negative selection. Surface expression was analyzed by means of flow cytometry. We also studied the expression of CD69, CD44, and CD54 on basophils in bronchoalveolar lavage fluid and blood specimens from patients with asthma. Results: CD44 and CD54 were constitutively expressed on basophils and moderately upregulated by IL-3. On the other hand, CD69 expression was only weakly observed in freshly isolated basophils, but IL-3 induced extremely high levels of expression. Surface CD69 appeared rather slowly in comparison with CD63 and CD11b, and the induction of expression was completed within 24 hours. Basophil CD69 had no functional relevance, but it did have biological relevance. Whole blood basophils from asthmatic individuals expressed significantly higher levels of CD69 than did those from normal individuals. Furthermore, bronchoalveolar lavage fluid basophils showed higher levels of CD69 expression than did blood basophils from the same donors. Conclusion: CD69 expression on basophils was preferentially and strongly upregulated by IL-3. CD69 on basophils might be useful as an in vitro as well as in vivo marker of activation of these cells by IL-3